Monitoring women late in pregnancy to predict labor and delivery is a vital part of pregnancy management for the safety of both the mother and child. A common method currently used by physicians for predicting if delivery is imminent is an external tocometer. A tocometer is a non-invasive device that is wrapped around the belly of a pregnant woman like a large elastic belt and measures the frequency of uterine contractions via strain gauge pressure sensor. The tocometer is comprised of an instrument that measures pressure changes in the abdomen of the patient. As a contraction takes place, the muscles under the skin contract, and a detectable pressure change is recorded by the tocometer. Both the strength and duration of a contraction can be indirectly measured based on the change in pressure in the abdomen. One disadvantage to the tocometer is that it must be strapped around the abdomen of the patient and around the back, which makes it difficult to put on or maintain in a uniform position, and makes it susceptible to falling off as the patient moves. Every time the waist strap moves, the readings become distorted. Also, the tocometer is typically wired to a local computer to monitor the readings, tethering the patient to a confined area. In addition, once the fetus is in the lower pelvis at the end stages of delivery, the external pressure transducer does not detect accurate pressure variations and the tocometer is no longer useful.
Once the fetus has descended into the lower pelvis and is imminently ready for delivery, a second device is typically used which is inserted into the uterus. This device is known as an intrauterine pressure catheter (IUPC). The IUPC is comprised of a thin, cylindrical tube that is inserted into the uterus and measures contractions by the change in pressure in the cylindrical tube. The IUPC is capable of direct pressure measurements as the uterus is directly contracting on the device, as well as the fetus that is being delivered. The disadvantages of using an IUPC is that the measurement technique is invasive, places the patient at increased risk of infection due to an external probe placed in the uterus, and requires the patient to have her amniotic sack ruptured prior to insertion. In addition, similar to the tocometer, the patient is typically tethered to a computer.
In both the tocometer and IUPC, the patient is physically tethered to a computer in order to monitor the readings of each device. Therefore, the patients are typically restricted to a hospital setting, and home monitoring is not convenient. Smart phone applications have been developed for monitoring of uterine contractions where the user manually presses a button every time she feels a contraction, however, this is not only difficult to use, but compliance with such tools is quite poor, often rendering the data collected meaningless.
Moreover, additional technology is required to assess the health of the fetus. The health of the fetus is currently assessed via ultrasound, recording fetal heart rate tracings, examining the fetus for characteristic movement patterns, as well as other methods. However, no universal technology or technique is capable of providing the full gamut of these tests, each of which involves bulky equipment typically restricted to a hospital setting.
Notwithstanding the advantages of prior fetal monitoring techniques, there is a need for a mechanically and electronically improved, simple to operate fetal monitoring system useful for the non-professional consumer and medical professionals alike. The present disclosure fulfills this need and provides further related advantages, as described below.